Test results - Codility

Tasks Details

medium

1. MissingInteger

Find the smallest positive integer that does not occur in a given sequence.

Task Score

100%

Correctness

100%

Performance

100%

This is a demo task.

Write a function:

def solution(A)

that, given an array A of N integers, returns the smallest positive integer (greater than 0) that does not occur in A.

For example, given A = [1, 3, 6, 4, 1, 2], the function should return 5.

Given A = [1, 2, 3], the function should return 4.

Given A = [−1, −3], the function should return 1.

Write an efficient algorithm for the following assumptions:

N is an integer within the range [1..100,000];

each element of array A is an integer within the range [−1,000,000..1,000,000].

Solution

Programming language used Python

Time spent on task 2 minutes

Notes

not defined yet

Code: 06:50:29 UTC, java, autosave

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// you can also use imports, for example:
// import java.util.*;

// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");

class Solution {
    public int solution(int[] A) {
        // write your code in Java SE 8
    }
}

Code: 06:50:36 UTC, py, autosave

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# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    pass

Code: 06:51:55 UTC, py, autosave

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# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    occurrence = [False] * (len(A) + 1)
    for item in A:
        if 1 <= item <= len(A) + 1:
            occurrence[item-1] = True
    # Find out the missing minimal positive integer.
    for index in xrange(len(A) + 1):
        if occurrence[index] == False:
            return index + 1
    raise Exception("Should never be here.")
    return -1

Code: 06:52:02 UTC, py, verify, result: Failed

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    occurrence = [False] * (len(A) + 1)
    for item in A:
        if 1 <= item <= len(A) + 1:
            occurrence[item-1] = True
    # Find out the missing minimal positive integer.
    for index in xrange(len(A) + 1):
        if occurrence[index] == False:
            return index + 1
    raise Exception("Should never be here.")
    return -1

Analysis

expand all Example tests

▶

example1
first example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.036 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

Traceback (most recent call last):
  File "exec.py", line 129, in <module>
    main()
  File "exec.py", line 91, in main
    result = solution( A )
  File "/tmp/solution.py", line 11, in solution
    for index in xrange(len(A) + 1):
NameError: name 'xrange' is not defined

▶

example2
second example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.036 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

Traceback (most recent call last):
  File "exec.py", line 129, in <module>
    main()
  File "exec.py", line 91, in main
    result = solution( A )
  File "/tmp/solution.py", line 11, in solution
    for index in xrange(len(A) + 1):
NameError: name 'xrange' is not defined

▶

example3
third example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.036 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

Traceback (most recent call last):
  File "exec.py", line 129, in <module>
    main()
  File "exec.py", line 91, in main
    result = solution( A )
  File "/tmp/solution.py", line 11, in solution
    for index in xrange(len(A) + 1):
NameError: name 'xrange' is not defined

Code: 06:52:15 UTC, py, verify, result: Passed

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# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    occurrence = [False] * (len(A) + 1)
    for item in A:
        if 1 <= item <= len(A) + 1:
            occurrence[item-1] = True
    # Find out the missing minimal positive integer.
    for index in range(len(A) + 1):
        if occurrence[index] == False:
            return index + 1
    raise Exception("Should never be here.")
    return -1

Analysis

expand all Example tests

▶

example1
first example test

✔

0.036 s

▶

example2
second example test

✔

0.036 s

▶

example3
third example test

✔

0.036 s

Code: 06:52:24 UTC, py, verify, result: Passed

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    occurrence = [False] * (len(A) + 1)
    for item in A:
        if 1 <= item <= len(A) + 1:
            occurrence[item-1] = True
    # Find out the missing minimal positive integer.
    for index in range(len(A) + 1):
        if occurrence[index] == False:
            return index + 1
    raise Exception("Should never be here.")
    return -1

Analysis

expand all Example tests

▶

example1
first example test

✔

0.036 s

▶

example2
second example test

✔

0.036 s

▶

example3
third example test

✔

0.036 s

Code: 06:52:26 UTC, py, final, score: 100

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    occurrence = [False] * (len(A) + 1)
    for item in A:
        if 1 <= item <= len(A) + 1:
            occurrence[item-1] = True
    # Find out the missing minimal positive integer.
    for index in range(len(A) + 1):
        if occurrence[index] == False:
            return index + 1
    raise Exception("Should never be here.")
    return -1

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

O(N) or O(N * log(N))

expand all Example tests

▶

example1
first example test

✔

0.036 s

▶

example2
second example test

✔

0.036 s

▶

example3
third example test

✔

0.036 s

expand all Correctness tests

▶

extreme_single
a single element

✔

0.036 s

▶

simple
simple test

✔

0.036 s

▶

extreme_min_max_value
minimal and maximal values

✔

0.036 s

▶

positive_only
shuffled sequence of 0...100 and then 102...200

✔

0.036 s

▶

negative_only
shuffled sequence -100 ... -1

✔

0.036 s

expand all Performance tests

▶

medium
chaotic sequences length=10005 (with minus)

✔

0.048 s

0.044 s

0.048 s

▶

large_1
chaotic + sequence 1, 2, ..., 40000 (without minus)

✔

0.140 s

▶

large_2
shuffled sequence 1, 2, ..., 100000 (without minus)

✔

0.152 s

▶

large_3
chaotic + many -1, 1, 2, 3 (with minus)

✔

0.140 s